Reports of smoke on the tracks at Metro Center starting at about 9:20 a.m. caused major delays on the Red Line this morning, with trains sharing the same track between Judiciary Square and Farragut North. WMATA says the situation had been resolved by about 9:40 a.m., but delays persist in both directions on the Red Line. UPDATE 11:09 a.m.: Metro says the cause of the smoke at Metro Center this morning was a fire that broke out after one of the train’s collector shoes, which are attached to the third rail, fell off. WMATA is investigating what could have caused such a piece of equipment to disconnect from the train. Each train has four collector shoes.